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A comment on Boeing 737 MAX crash and the rejection of ridiculous data.

Re:Boeing 737 MAX crash and the rejection of ridiculous data by yongjik on Wednesday April 10, 2019 @02:59PM (#19627718)
With all due respect, this sounds too much like the kind of armchair quarterbacking that routinely appears on HN when avionics/politics/astronomy is mentioned, where a lone programmer feels competent enough to criticize an industry for missing "something obvious".

I mean, this particular change might have saved the particular 737, but I'd rather hear it from someone who actually knows how 737s fly.

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by js2 on Wednesday April 10, 2019 @03:05PM (#19627763)
Philip Greenspun is a highly experienced pilot:

https://philip.greenspun.com/flying/milestones

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by mtnGoat on Wednesday April 10, 2019 @03:18PM (#19627871)
I too have hundreds of flights and am also a programmer, but I would not assume having both skills would make you anything more then an armchair quarterback. If you have not written code that runs planes, what knowledge are you basing your idea off of. IMO.

i too also play games, but i wouldn't assume to tell a game developer how to write their code.

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by MFLoon on Wednesday April 10, 2019 @05:25PM (#19628949)
I agree - being a pilot and a programmer is neither a necessary nor sufficient condition for being able to diagnose and solve an issue in a system as complex as a modern airliner. In fact I don't think any individual is capable of doing so on their own; maybe the sole exception being someone like the engineering lead of avionics for the 737 Max, who is probably not a pilot, and probably only a programmer in so far as it was a component of their engineering education.
[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by sk5t on Wednesday April 10, 2019 @03:39PM (#19628061)
Honest question, is his experience in small aircraft applicable at all to jetliners? How much carryover, beyond core theory of flight dynamics, is there from piloting a single prop to an Airbus or even a regional jet?
[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by scarhill on Wednesday April 10, 2019 @04:15PM (#19628361)
His resume includes:

- FAA ATP AMEL and ASEL certificate with CL-65 SIC rating and Part 121 experience; CE-510S rating (single pilot, Cessna Mustang)

- Helicopter ATP

- single-engine seaplane rating at the commercial level

- FAA Flight Instructor certificate with airplane single-engine, airplane multi-engine, helicopter, instrument airplane, and instrument helicopter ratings

He has also worked as a commercial pilot for Delta/Comair. See https://philip.greenspun.com/flying/resume

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by VBprogrammer on Wednesday April 10, 2019 @04:10PM (#19628327)
He part owns a Pilatus PC-12, which is pretty much a single engine regional jet. It isn't your grandfather's Cessna.
[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by et2o on Thursday April 11, 2019 @08:59AM (#19633970)
Turboprop
[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by js2 on Wednesday April 10, 2019 @04:14PM (#19628352)
He has first officer experience flying a CL-65 Canadair Regional Jet.
[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by fixermark on Wednesday April 10, 2019 @03:11PM (#19627806)
He doesn't seem to be an experienced owner of a home outdoor thermometer though.

Or if he is, I need to know where he found one that goes to 452 degrees and why he even needs that much range. ;)

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by squarefoot on Wednesday April 10, 2019 @03:27PM (#19627954)
The thermometer sensor and circuitry might be perfectly ok, still the 452 number might be a single digit gone bonkers in the panel, so that data being transmitted (maybe also recorded?) is ok while the readout is plain wrong. A human acting according data being shown there might react very differently from someone reading the temperatures log. Sometimes software problems can be awfully subtle.
[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by navila17 on Wednesday April 10, 2019 @03:26PM (#19627945)
Digital thermometers usually have triple digits to be able to display numbers in the low 100's. I could see one of them failing in a weird way and displaying 452.
[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by depressed on Wednesday April 10, 2019 @09:28PM (#19630333)
I was as confused as the other commentators by this post until I realized that fixermark is thinking of analog thermometers with a physical dial, while we (and probably the author as well) are envisioning electronic thermometers with digital displays.
[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by lepton on Wednesday April 10, 2019 @03:27PM (#19627949)
BBQ lid? Many have thermometers that go higher than this (say, 700F), and they're often outdoors.
[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by darkpuma on Wednesday April 10, 2019 @03:34PM (#19628019)
How else would you know there is a wildfire outside?
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Re:Boeing 737 MAX crash and the rejection of ridiculous data by falcolas on Wednesday April 10, 2019 @03:11PM (#19627807)
A pilot is not a programmer. A minor, but important distinction.

EDIT: Aaaand I'm an idiot. My bad.

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by Zak on Wednesday April 10, 2019 @03:13PM (#19627839)
Philip Greenspun is, in fact a programmer. He's probably best known in these circles for the quote "Any sufficiently complicated C or Fortran program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp."

It is possible to be both a pilot and a programmer.

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by fixermark on Wednesday April 10, 2019 @03:18PM (#19627875)
This is referred to in the industry as a "Dr. McNinja scenario."

(... nobody refers to it as that ;) ).

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by adolph on Wednesday April 10, 2019 @03:15PM (#19627856)
Are you claiming Greenspun is not a programmer?

https://en.wikipedia.org/wiki/ArsDigita

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by supergauntlet on Wednesday April 10, 2019 @03:15PM (#19627854)
https://philip.greenspun.com/teaching/

not only is he a programmer, but he has opinions on teaching programming.

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by noxryan on Wednesday April 10, 2019 @03:04PM (#19627761)
I agree that we frequently see this on HN in regards to aviation. However, I don;t think it applies to Greenspun. He's a knowledgeable and active pilot himself.
[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by bilbo0s on Wednesday April 10, 2019 @03:27PM (#19627948)
Lots of people are, that doesn't mean they aren't armchair quarterbacking. I know how to fly airplanes and helicopters, does that make me an expert on the flight dynamics of 737 MAX?
[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by starpilot on Wednesday April 10, 2019 @03:50PM (#19628158)
According to Wikipedia he flew for Delta Airlines/Comair https://en.wikipedia.org/wiki/Philip_Greenspun.

That still doesn't mean he knows anything about writing code for flight control systems in commercial environments. Maybe he's written some toy code in MATLAB demonstrating some things, that's never undergone testing on a real airframe.

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by tzs on Wednesday April 10, 2019 @05:43PM (#19629096)
Are there any airliners for which a sustained 60-70 degree angle of attack over a span of several minutes is not overwhelmingly likely due to sensor failure?
[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by VBprogrammer on Wednesday April 10, 2019 @04:05PM (#19628280)
I think it's fair to say that his knowledge of aircraft plus his knowledge of software and electrical engineering qualify him to speculate.

Its quite likely he has greater knowledge of both subjects than the person who physically implemented MCAS.

Sadly, no speculation is necessary. Had that change been included in MCAS the Ethiopian crash wouldn't have happened.

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by joezydeco on Wednesday April 10, 2019 @10:33PM (#19630646)
However, any programmer that's been around the block a few times knows when they see a phrase like

"all of the problems on the Ethiopian flight could potentially have been avoided by changing....about 10 characters of code"

It's a sign that things are never as simple as they seem on the surface.

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by ronilan on Wednesday April 10, 2019 @03:13PM (#19627831)
Down by 4 at the Super Bowl, 2nd & Goal, 27 seconds on the play clock, Lynch in the back field.

  Run the ball
About 10 characters of code. Sometimes armchair quarterbacking has a point.
[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by greedo on Wednesday April 10, 2019 @03:14PM (#19627844)
As a Hawks fan, that hurt. Really hurt.
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Re:Boeing 737 MAX crash and the rejection of ridiculous data by ronilan on Wednesday April 10, 2019 @03:18PM (#19627870)
The agony: https://www.youtube.com/watch?v=U7rPIg7ZNQ8
[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by aidenn0 on Wednesday April 10, 2019 @11:44PM (#19630985)
Even there though, the fact that the Pats scout team ran that exact play twice in practice with the backup nickelback in was something that the coach perhaps could not have anticipated?

Any result other than an INT means Lynch still has a chance to run.

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by phdp on Wednesday April 10, 2019 @03:07PM (#19627779)
Philip Greenspun is not a no one when it comes to aviation.

https://philip.greenspun.com/flying/resume

While he doesn't have 737 experience, he's far from an armchair quarterback.

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by gowld on Wednesday April 10, 2019 @03:04PM (#19627754)
Do you think the analysis is invalid?

Do you think that an autopilot response to "AOA > 15 degrees" should be the same regardless of whether AOA is 20, 40, 60, or 80 degrees?

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by astrodust on Wednesday April 10, 2019 @03:07PM (#19627780)
Is there an industrial coding standard that makes recommendations here?

What does NASA do?

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by itronitron on Wednesday April 10, 2019 @03:35PM (#19628025)
a common practice is to limit the number of bits in the data value which will limit the range of values it can have
[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by salawat on Wednesday April 10, 2019 @07:02PM (#19629541)
This type of elitism has no real place in hopefully constructive conversation.

I'm not going to ignore a well thought out point because someone doesn't have a PhD in the exact question under rumination.

And "armchair quarterbacking" tends to translate to "Request For Comment" in my book. I.e. a coming together of disparate ideas and areas of expertise to more fully render the extent of a problem.

[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by sesteel on Wednesday April 10, 2019 @03:17PM (#19627866)
This seems equivalent to "it is just a button, how hard can it be?" People outside of software rarely see the complexity they are suggesting or asking for.
[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by Zak on Wednesday April 10, 2019 @03:05PM (#19627764)
Philip Greenspun is, in fact a pilot. He is not a 737 pilot, but probably has a better idea of how a 737 works than the average HN armchair quarterback.
[ Parent | on HN ]
Re:Boeing 737 MAX crash and the rejection of ridiculous data by gamache on Wednesday April 10, 2019 @03:04PM (#19627756)
philg's been flying and writing about it for years: https://philip.greenspun.com/flying/
[ Parent | on HN ]